This invention relates to a two component activator for a polymerization catalyst.
This invention relates to catalyst activation for olefin polymerizations.
It is now well known to use an aluminoxane, especially a methylaluminoxane, to activate olefin polymerization catalysts containing group 3-10 metal complexes (particularly those metal complexes which contain delocalized pi ligands and are known as xe2x80x9cmetallocene catalystsxe2x80x9d).
It is also known to use organoboron activators for olefin polymerization catalysts. Tris (pentafluorophenyl) borane, and near derivatives thereof, are particularly well known in this regard. Salts of tetrakis (pentafluorophenyl) boron are similarly employed. The tris (pentafluorophenyl) borane activators are desirable for use in solution polymerization (because of their excellent solubility). The borate salts generally offer higher polymerization activities but are difficult to use in solution polymerizations because of their low solubilities in non polar solvents.
In addition, all of the aforementioned activators are expensive.
Accordingly, it would be desirable to improve the performance of prior art activators, especially with respect to lowering the cost of the activators and improving the solubility of highly active boron activators for solution polymerizations.
The present invention provides a catalyst activator comprising:
1) a Lewis acid component defined by the formula ML1L2L3 wherein M is boron or aluminum; each of L1, L2 and L3 is independently selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, hydrocarboxylide and substituted hydrocarboxylide; and L3 is selected from the group consisting of hydrocarbyl, substituted hydrocarbyl, hydrocarboxylide, substituted hydrocarboxylide, amino, phosphido, siloxy, sulfido and halide; and
2) a second component defined by the formula AOSO2R where A is a pseudo cationic group and R is hydrocarbyl or substituted hydrocarbyl.
The activator of this invention is particularly useful for the polymerization of addition polymerizable monomers (especially monoolefins) in the presence of a transition metal catalyst. Catalysts based on group 4 metals are preferred. Thus, another embodiment of this invention provides a catalyst system comprising:
1) a catalyst activator as above; and
2) a catalyst comprising a group 3-10 metal complex.
A third embodiment of this invention provides a process for the polymerization of olefins.